1. Field of the Invention
The present invention relates to an adaptive optical apparatus, an image obtaining apparatus, a method for controlling the adaptive optical apparatus, and a storage medium, and particularly relates to a technology for correcting aberrations generated by an object to be examined.
2. Description of the Related Art
In recent years, the technology of adaptive optics (AO) that corrects even higher-order wavefront aberrations using an active optical element has been put to practical use and applied in various fields. This technology successively measures wavefront aberrations of probe light or signal light, which may be generated due to the characteristics of a measurement target itself, variations in a measurement environment, and the like, using a wavefront sensor and corrects the wavefront aberrations using a wavefront corrector such as a deformable mirror (hereinafter referred to as “DM”), a spatial light modulator (hereinafter referred to as “SLM”), or the like, and is receiving attention especially in the field of systems for examination of the eye's retina.
As examples of such ophthalmic devices, in addition to a fundus camera, an SLO (Scanning Laser Ophthalmoscope) that obtains a two-dimensional image of the retina and an OCT (Optical Coherence Tomography) that obtains a tomographic image of the retina are known. The SLO and the OCT scan a light beam one- or two-dimensionally on the retina using a scanning unit, receive reflected and backscattered light from the retina, and obtain a two-dimensional image or a three-dimensional image of the retina.
Japanese Patent No. 4157839 discloses an SLO in which while a scanning unit two-dimensionally scans light from a light source on a retina, a wavefront detector receives a part of returning light reflected from the retina and detects a wavefront, an aberration corrector corrects the wavefront of light irradiated onto an eye to be examined and the wavefront of the returning light, and a part of the returning light is received to form an image.
Here, generally, a DM of a type having a configuration in which a plurality of micromirrors are periodically and two-dimensionally arrayed or a liquid crystal type SLM in which a plurality of micropixels are periodically arrayed in a two-dimensional matrix is used as the aberration corrector that corrects the wavefront aberrations. Since these aberration correctors have a structure in which gaps are periodically distributed among the plurality of pixels, diffracted light will be generated when the aberration corrector is irradiated with light. If the wavefront detector is irradiated with the diffracted light, precise wavefront detection may be affected, resulting in a decrease in the accuracy of aberration correction, and thus there is a possibility that the image quality of the obtained image may also decrease.